<%@ page contentType="image/jpeg charset=UTF-8"
	pageEncoding="UTF-8" import="java.awt.*, java.awt.image.*,java.util.*,javax.imageio.*"%>
<%! 
	Color getRandColor(int fc,int bc) 
	{ 
		Random random = new Random(); 
		if(fc>255) fc=255; 
		if(bc>255) bc=255; 
		int r=fc+random.nextInt(bc-fc); 
		int g=fc+random.nextInt(bc-fc); 
		int b=fc+random.nextInt(bc-fc); 
		return new Color(r,g,b); 
	} 
	%>
	<% 
		out.clear();//这句针对resin服务器，如果是tomacat可以不要这句 
		response.setHeader("Pragma","No-cache"); 
		response.setHeader("Cache-Control","no-cache"); 
		response.setDateHeader("Expires", 0); 
		int width=60, height=20; 
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
		Graphics g = image.getGraphics(); 
		Random random = new Random(); 
		g.setColor(getRandColor(200,250)); 
		g.fillRect(0, 0, width, height); 
		g.setFont(new Font("Times New Roman",Font.PLAIN,18)); 
		g.setColor(getRandColor(160,200)); 
		for (int i=0;i<155;i++) 
		{ 
		int x = random.nextInt(width); 
		int y = random.nextInt(height); 
		int xl = random.nextInt(12); 
		int yl = random.nextInt(12); 
		g.drawLine(x,y,x+xl,y+yl); 
		} 
		String sRand=""; 
		for (int i=0;i<4;i++){ 
		String rand=String.valueOf(random.nextInt(10)); 
		sRand+=rand; 
		g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110))); 
		g.drawString(rand,13*i+6,16); 
		} 
		// 将认证码存入SESSION 
		session.setAttribute("rand",sRand); 
		g.dispose(); 
		ImageIO.write(image, "JPEG", response.getOutputStream()); 
%>